poly(I).(C) is a double-stranded RNA consisting of polyinocinic acid and polycytidylic acid is broadly known to be a medicinally active substance having interferon-inducing activity and immunopotentiating activity.
It has recently been reported that interferon itself is effective in the treatment of hepatitis C (e.g., KAN-TAN-SUI, 9(4), 611 (1984); ibid., 13(1), 123 (1986); ibid., 12(5), 809 (1986); ibid., 23(5), 1065 (1991)). It is, however, difficult to treat hepatitis C with poly(I).poly(C) capable of inducing interferon just by conventional administration methods, in view of the extent of interferon induction, toxicity, and the like.
On the other hand, there are known pharmaceutical- or drug-carriers including those generally called cationic liposomes such as LIPOFECTIN (registered trademark) and those composed of a glycerol derivative such as 2-O-(2-diethylaminoethyl)carbamoyl-1,3-O-dioleoylglycerol of the following chemical formula [I] and a phospholipid as essential components [e.g. PCT WO91/17424, PCT WO94/19314].

The cationic liposome is considered to be a small vesicle composed of lipid bimolecular layer and charged positively in an aqueous solution. Since a cationic liposome becomes positively charged while a double-stranded RNA such as poly(I).poly(C) negatively charged in an aqueous solution, a cationic liposome and poly(I).poly(C), for instance, may easily form a complex when subjected to a typical dispersing treatment.
However, it is not known at all whether a complex of a double-stranded RNA such as poly(I).poly(C) with a drug carrier like the above-mentioned cationic liposome would be effective in the treatment of hepatitis and the like.